Although most children learn to read with relative ease, others have great difficulty. Early reading problems often have a negative impact on later academic and economic advancement, and may potentially reduce quality of life. Research indicates that deficits in phonological awareness, one's sensitivity to the sound structure of language, underlies most early reading difficulties. However, little is known concerning the emergence of phonological awareness. This study will investigate the phonological and lexical processing of three groups of preschool children differing in phonological awareness or age. A word learning task will be employed in which children's responses to nonwords will be examined as these nonwords become lexicalized. The specific aims of this study address three questions: Do children differing in phonological awareness/age (1) show differences in the phonological processing of nonwords? (2) exhibit differences in lexical processing during word learning? and/or (3) evidence differences in the lexical representations of newly learned words? The long-term goal is to improve the understanding of the emergence of phonological awareness and aid in the early identification and intervention for children at risk for reading disabilities.